1) Disconnect the collation CM connector and the oscillator connector.
2) Using a tester, check continuity between the collation CM connector and oscillator connector.
Connector & terminal
(B421) No. 5 — (D55) No. 4: (B421) No. 22 — (D55) No. 6:
Is there continuity?
Repair or replace the open circuit of harness.